One problem associated with vehicles crossing rough terrain is the amount of travel required of the suspension system. Unless virtually unlimited travel of the suspension system is provided which is impracticable, when the suspension system reaches its limit of travel there will be contact of one component against another component which produces a jolting ride and ultimately fatigue of the components contacting each other as well as loss of traction and less control of the vehicle. In conventional suspension systems having metal springs, even variable rate metal springs, such as coil springs or auxiliary springs, owing to the compression/rebound characteristics of the metal springs, the suspension often reaches its limit of travel so that components of the suspension system contact the body of the vehicle, such as for example, the suspension arms contacting the bump stop provided on the vehicle or the vehicle “bottoms out”. When this occurs, not only are the occupants of the vehicle jolted or the freight being carried by the vehicle subject to shock, but also the contact of the various individual suspension components against each other from time to time breaks one or more of the suspension components or the body or chassis of the vehicle. Broken suspension components can occur in diverse areas of activities such as in off-road racing where vehicles must travel fast over rough terrain, in the mining industry where extremely heavy loads must be transported over rough terrain in harsh and corrosive environments, and in military applications where men and equipment must be transported in arduous conditions, even including parachuting vehicles, such as four wheel drives, jeeps and the like from low flying aeroplanes onto the ground where the vehicles land with a jolt, often disabling the vehicle and equipment loaded with the vehicle due to the limited compliance of the suspension systems of such vehicles.
In many applications it is desirable to have a more supple suspension even though the vehicle is used in a harsh environment. In these applications not only must the suspension components be durable and reliable but the ride must also be substantially smooth or at least the suspension must not reach the limits of its travel or “bottom out”. Therefore, it is one aim of the present invention to provide a suspension system which can be used in harsh environments such as rough terrain and which provides a supple ride, particularly without the use of metal springs or other components.
Another problem of existing conventional suspension systems having metal springs or similar components relates to the ride height of the vehicle and the adjustability of the ride height. In many instances, the ride vehicle which is not adjustable is set by the various components of the suspension, such as the coil spring or the like. In order to change the ride height it is necessary to physically interchange components which is expensive, time consuming and wasteful of materials and components. Often the ride height of a vehicle, such as an off road racing vehicle, will need to be adjusted quickly one or more times during the same event. Conventional suspensions do not usually allow such adjustments to be made quickly. Therefore, there is a need for a suspension system that allows the ride height of a vehicle to be adjusted, particularly adjusted quickly and effectively.
In other applications, such as for example, in normal domestic vehicles of the type which are privately owned or in motor cycles, there is a need for suspensions which occupy a smaller space within the confines of the car, bike or similar and yet work at least as effectively as more conventional suspensions in ordinary everyday driving. Thus, there is a need for a more compact suspension system which occupies less room on or within a vehicle and also provides acceptable ride and comfort, which suspension system can be adapted for use in normal road going cars.